Advanced AI only works for creatures. Double click on the creature's icon to open up its properties page. Along the top will be it's attitude buttons (peaceful, neutral, etc.) Ctrl+click on any one of those to bring up advanced AI

Doors to "enter" buildings are done with invisible teleporters. Place a teleporter (load under the gameplay objects menu) in front of the door, and put the other end where you've designed the interrior. Doubleclick to open up properties, and set from "normal" to "invisible" in the little drop-down box below the picture.